i have fitted a pivot to car starter motor and chain to it and fitted to a drum cutter , for my robot. but my starter motor which is in good condition works for just a few seconds and as the wire heats it stops and then after cooling down of wire it again starts. any solution for this. i have tried a wire of 10sqmm gauge copper.

Wed Jan 22, 2014 2:54 am

NickExperienced Roboteer

Joined: 16 Jun 2004
Posts: 11799
Location: Sydney, NSW

Starter motors are a bad choice to power weapons; they are only meant to run for short periods and will overheat quickly, as you are seeing. The motor may have a thermal cut-out inside it that is stopping the motor before it overheats too much.

If you can tell us a bit more about the weapon (weight, diameter, RPM, etc.) then we can probably suggest the best type of motor for you.

Wed Jan 22, 2014 9:07 am

ValenExperienced Roboteer

Joined: 07 Jul 2004
Posts: 4433
Location: Sydney

sounds more like an internal polyfuse or something than a hot wire.
Normally hot wires just get hotter._________________Mechanical engineers build weapons, civil engineers build targets

Wed Jan 22, 2014 12:03 pm

anshulmahale1

Joined: 20 Jan 2014
Posts: 6

Using starter motor with chain system for cutter (weapon)

i have already fixed the motor nd it gives a very good out put. and it doesnt have any thermal control. its a simple brush motor. prob is that the wire is not supporting. incase any body can suggest anything about wires incase u suggest any other motor than, its a 500 g, drum cutter

Thu Jan 23, 2014 1:25 am

JaemusExperienced Roboteer

Joined: 01 Apr 2009
Posts: 2674
Location: NSW

Thicker wire?_________________<Patrician|Away> what does your robot do, sam
<bovril> it collects data about the surrounding environment, then discards it and drives into walls

Thu Jan 23, 2014 12:48 pm

NickExperienced Roboteer

Joined: 16 Jun 2004
Posts: 11799
Location: Sydney, NSW

10sq mm is around 8 to 10 gauge wire - if that is heating up too much then even if thicker wire helps, the current draw is so high that huge batteries will be needed to power the motor for a whole match. Do you really mean the drum weights 500 grams? that is tiny to be powered by a starter motor!

Just having the wiring get hot will not stop the motor running - something else must also be overheating and going open-circuit. What type of battery are you using?

Thu Jan 23, 2014 3:40 pm

anshulmahale1

Joined: 20 Jan 2014
Posts: 6

i m using a car battery. and according to a electrician the motor is perfectly fine